OPTIMUM DISCRETE DISTRIBUTED BEAMFORMING FOR SINGLE GROUP MULTICASTING RELAY NETWORKS WITH RELAY SELECTION

2015-04-24
Demir, Özlem Tuğfe
Tuncer, Temel Engin
In this paper, broadcast beamforming with relay selection is considered in wireless relay networks where there is no direct link between the source and the receivers. A source node transmits common information to many users employing multiple relays which use amplify-and-forward relay protocol. The channel state information is assumed to be available at a single relay to compute the relay weights and distribute them. Discrete relay weights are used due to several advantages including decreased overhead for the feedback channel. Multiple relay selection is employed in order to decrease network complexity and improve bandwidth efficiency. Nonlinear joint optimization problem is converted to a liner form and optimum solution is found by using mixed integer linear programming.

Suggestions

Discrete Relay Beamforming for Broadcasting with Relay Selection
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2015-05-19)
In this paper, broadcast beamforming problem is considered in relay-assisted wireless networks. Two-phase relay communication is adopted. In the first phase, a source transmits common information to multiple relays which use amplify-and-forward relay protocol. Each relay multiplies its received signal by a complex weight and transmits it to the receivers. The amplitudes and phases of complex relay weights are chosen from discrete sets in order to decrease overhead for the feedback channel. Relay selection i...
Relay-Assisted Beamforming for Multicast Systems with Energy Harvesting Capability
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2016-05-19)
In this paper, multi-group multicasting scenario is considered where single antenna sources transmit their own information to different groups of users with the help of single antenna relays. Users have energy harvesting capability, i.e., a part of the received signal is used for information decoding while the rest is used for energy harvesting. Beamforming is performed by the relays which use amplify-and-forward protocol. The design of complex relay coefficients and power splitting ratios for the users is ...
DISTRIBUTED BEAMFORMING IN RELAY NETWORKS FOR ENERGY HARVESTING MULTI-GROUP MULTICAST SYSTEMS
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2016-03-25)
In this paper, simultaneous wireless information and power transfer (SWIPT) is considered for multi-group multicasting relay networks where there is no direct link between the source and destination nodes. Each source transmits its own multicast stream to a group of users with the help of single antenna relays which use amplify-and-forward relay protocol. Each user has energy harvesting capability. A part of the received signal is used for information decoding while the rest is used for energy harvesting. T...
Optimum discrete phase-only multicast beamforming with joint antenna and user selection in cognitive radio networks
DEMİR, ÖZLEM TUĞFE; Tuncer, Temel Engin (2015-11-01)
Spectrum underlay technique for secondary multicast network is an effective approach in cognitive radio. In such communication schemes, quality of service constraints are satisfied for the secondary users while interference to the primary users is kept under a threshold. Previous literature consists of suboptimum methods for the solution of the individual problems such as antenna and user selection. In this paper, the joint antenna and user selection problem is considered and solved in an optimum manner. Co...
HYBRID BEAMFORMING WITH TWO BIT RF PHASE SHIFTERS IN SINGLE GROUP MULTICASTING
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2016-03-25)
In this paper, an efficient hybrid beamforming architecture combining analog and digital beamforming is proposed to reduce the number of radio frequency (RF) chains. It provides a good compromise between the higher degree of freedom of digital beamforming and hardware cost and complexity. In this hybrid system, two bit RF phase shifters are used as analog beamformers due to the fact that this enables the conversion of the combinatorial optimization problem to a continuous programming formulation. The overal...
Citation Formats
Ö. T. Demir and T. E. Tuncer, “OPTIMUM DISCRETE DISTRIBUTED BEAMFORMING FOR SINGLE GROUP MULTICASTING RELAY NETWORKS WITH RELAY SELECTION,” 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53722.